1. Field of the Invention
This invention relates to a process for preparing halogenated metal chelates of beta-dicarbonyl compounds, and particularly the synthesis of tris-(3-bromo acetylacetonato) metal (III) compounds.
2. Description of the Prior Art
U.S. Pat. No. 3,014,939 discloses as prior art that halogenated analogues of metal chelates of beta-dicarbonyl compounds can be prepared by reacting a halogenated chelate or ligand with a metal salt and that chromium acetylacetonates can be brominated by direct bromination. The patent, however, was granted on the basis that halogenation of the metal chelate of beta-dicarbonyl compounds could be effected by reacting the metal chelate with an N-halogenated cyclic amide such as N-bromosuccinimide.
Other authors have disclosed methods for producing the brominated metal chelates of beta-dicarbonyl compounds by reacting elemental bromine with the metal chelate in the presence of glacial acetic acid. (Presumably, this is the process referred to in U.S. Pat. No. 3,014,939.) The basic problem with this process is that the product decomposes in the glacial acetic acid, and as a result, low yields are experienced.